0N/A/*
3833N/A * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
0N/A *
0N/A * Redistribution and use in source and binary forms, with or without
0N/A * modification, are permitted provided that the following conditions
0N/A * are met:
0N/A *
0N/A * - Redistributions of source code must retain the above copyright
0N/A * notice, this list of conditions and the following disclaimer.
0N/A *
0N/A * - Redistributions in binary form must reproduce the above copyright
0N/A * notice, this list of conditions and the following disclaimer in the
0N/A * documentation and/or other materials provided with the distribution.
0N/A *
2362N/A * - Neither the name of Oracle nor the names of its
0N/A * contributors may be used to endorse or promote products derived
0N/A * from this software without specific prior written permission.
0N/A *
0N/A * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
0N/A * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
0N/A * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
0N/A * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
0N/A * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
0N/A * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
0N/A * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
0N/A * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
0N/A * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
0N/A * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
0N/A * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
0N/A */
0N/A
4378N/A/*
4378N/A * This source code is provided to illustrate the usage of a given feature
4378N/A * or technique and has been deliberately simplified. Additional steps
4378N/A * required for a production-quality application, such as security checks,
4378N/A * input validation and proper error handling, might not be present in
4378N/A * this sample code.
4378N/A */
4378N/A
4378N/A
0N/A
0N/A/**
0N/A * A quick sort demonstration algorithm
0N/A * SortAlgorithm.java
0N/A *
0N/A * @author James Gosling
0N/A * @author Kevin A. Smith
0N/A */
3833N/Apublic class QSortAlgorithm extends SortAlgorithm {
0N/A
0N/A /**
0N/A * A version of pause() that makes it easier to ensure that we pause
0N/A * exactly the right number of times.
0N/A */
0N/A private boolean pauseTrue(int lo, int hi) throws Exception {
0N/A super.pause(lo, hi);
0N/A return true;
0N/A }
0N/A
3833N/A /** This is a generic version of C.A.R Hoare's Quick Sort
3833N/A * algorithm. This will handle arrays that are already
3833N/A * sorted, and arrays with duplicate keys.<BR>
3833N/A *
3833N/A * If you think of a one dimensional array as going from
3833N/A * the lowest index on the left to the highest index on the right
3833N/A * then the parameters to this function are lowest index or
3833N/A * left and highest index or right. The first time you call
3833N/A * this function it will be with the parameters 0, a.length - 1.
3833N/A *
3833N/A * @param a an integer array
3833N/A * @param lo0 left boundary of array partition
3833N/A * @param hi0 right boundary of array partition
3833N/A */
3833N/A void QuickSort(int a[], int lo0, int hi0) throws Exception {
3833N/A int lo = lo0;
3833N/A int hi = hi0;
3833N/A int mid;
0N/A
3833N/A if (hi0 > lo0) {
0N/A
3833N/A /* Arbitrarily establishing partition element as the midpoint of
3833N/A * the array.
0N/A */
3833N/A mid = a[(lo0 + hi0) / 2];
3833N/A
3833N/A // loop through the array until indices cross
3833N/A while (lo <= hi) {
3833N/A /* find the first element that is greater than or equal to
3833N/A * the partition element starting from the left Index.
3833N/A */
3833N/A while ((lo < hi0) && pauseTrue(lo0, hi0) && (a[lo] < mid)) {
3833N/A ++lo;
3833N/A }
0N/A
3833N/A /* find an element that is smaller than or equal to
3833N/A * the partition element starting from the right Index.
3833N/A */
3833N/A while ((hi > lo0) && pauseTrue(lo0, hi0) && (a[hi] > mid)) {
3833N/A --hi;
3833N/A }
3833N/A
3833N/A // if the indexes have not crossed, swap
3833N/A if (lo <= hi) {
3833N/A swap(a, lo, hi);
3833N/A ++lo;
3833N/A --hi;
3833N/A }
0N/A }
0N/A
3833N/A /* If the right index has not reached the left side of array
3833N/A * must now sort the left partition.
3833N/A */
3833N/A if (lo0 < hi) {
3833N/A QuickSort(a, lo0, hi);
3833N/A }
0N/A
3833N/A /* If the left index has not reached the right side of array
3833N/A * must now sort the right partition.
3833N/A */
3833N/A if (lo < hi0) {
3833N/A QuickSort(a, lo, hi0);
3833N/A }
0N/A
3833N/A }
3833N/A }
0N/A
3833N/A private void swap(int a[], int i, int j) {
3833N/A int T;
3833N/A T = a[i];
3833N/A a[i] = a[j];
3833N/A a[j] = T;
0N/A
3833N/A }
3833N/A
3833N/A @Override
3833N/A public void sort(int a[]) throws Exception {
3833N/A QuickSort(a, 0, a.length - 1);
3833N/A }
0N/A}